The dental profession recommends certain general guidelines for brushing teeth with a conventional toothbrush. Teeth should be brushed in the morning, at night before retiring, and after meals. At least once during the day, the brushing should be performed continuously for ten minutes. During brushing, the biting surfaces and side surfaces of the teeth should be scrubbed, and the gingival sulcus, a narrow crevice beneath the gumline between the gingiva (gums) and the teeth, should be cleaned by aiming the bristles of the toothbrush at the gumline at a 45 degree angle from vertical. Preferably, the toothbrush is moved in a small circular motion to clean the gingival sulcus. Through this motion, the bristles work into the gingival sulcus and lift debris out of it. Pressure of the toothbrush against the area being cleaned should be gentle where cleaning the gingival sulcus and massaging the gums; the pressure may be somewhat greater where scrubbing the biting surfaces of the teeth.
These guidelines, although effective, are rarely followed. Most people do not brush nearly long enough; a typical person brushes his teeth for approximately one minute per day, which results in less than two seconds of brushing per tooth surface. This is inadequate for good oral hygiene. Additionally, most people do not implement the intricate brushing motion recommended by the above guidelines, which motion necessarily requires a high level of concentration and manual dexterity. Elderly, arthritic, or otherwise impaired persons may not be able physically to brush their teeth in the recommended manner.
A number of different types of brushes have been developed in an attempt to overcome these disadvantages. Many of these fit over and brush an entire arch of teeth at one time (there are two arches, or rows, of teeth in the mouth: an upper and a lower). Brushing an entire arch at once reduces the time required to brush all the exposed surfaces of the teeth. In many of these apparatuses, brushing is carried out by chewing motion while the brush is in the mouth. Examples of such apparatuses include U.S. Pat. No. 3,769,652 to Rainer, U.S. Pat. No. 4,237,574 to Kelly et al., and U.S. Pat. No. 3,874,084 to Cole. The chewing motion, however, is non-uniform, and there is no assurance that the bristles of the brush will move in the recommended way. Additionally, since the brushing device in all of these patents fits completely over the teeth (i.e., all the way down the sides thereof), the bristles projecting from the sides of the device that are used to brush the side surfaces of the teeth tend to stick straight out from the device and are therefore oriented perpendicular to the gumline instead of at the recommended 45 degrees.
A tooth brushing device disclosed in U.S. Pat. No. 4,011,616 to Kennedy addresses the problem of proper movement by carrying out brushing motion through a single connection to a vibratory device at the front of the arch. However, proper functioning requires that a rigid skeletal structure be placed along the length of the arch, which adds to the bulk of the device and increases user discomfort. A patent to Solow, U.S. Pat. No. 4,224,710, discloses a tooth brushing device that mechanically moves individual groups of bristles around each tooth. This apparatus, however, is bulky, and cleans the gingival sulcus with vertical motion only instead of the recommended circular motion.
There remains a need for a small convenient tooth brushing apparatus that can brush an entire arch of teeth at once, while carrying out the recommended tooth brushing motion.